: @Jan: I am using Debian 10 (Buster). I am switching to the solr user at the
based on the logs you posted, you seem to be building the docker container inside of some other build system... 1) are you certain you know exactly what command/options your build system is using to invoke 'docker build' ? 2) have you tried just building manually on the command line? 3) are you certain you are using the 'solr:9.2.1' from docker hub (and not sme other weird locally built version) ... have you tried 'docker build --pull ...' 4) do you have any firewall rules that might be allowing apt to talk to the ubuntu distribution servers, but not the keyserver? 5) This particular set of error msgs strike me as evience of something very, very wrong happening with your docker build, since the files in question is world readable inside the solr docker image... : 41593 [INFO] DOCKER> [91mhttp:// : security.ubuntu.com/ubuntu/dists/jammy-security/InRelease: The key(s) in : the keyring /etc/apt/trusted.gpg.d/ubuntu-keyring-2012-cdimage.gpg are : ignored as the file is not readable by user '_apt' executing apt-key. $ docker run --rm -it --entrypoint /bin/bash solr:9.2.1 -c 'ls -al /etc/apt/trusted.gpg.d/' total 16 drwxr-xr-x 2 root root 4096 Apr 25 14:06 . drwxr-xr-x 8 root root 4096 Apr 25 14:03 .. -rw-r--r-- 1 root root 2794 Mar 26 2021 ubuntu-keyring-2012-cdimage.gpg -rw-r--r-- 1 root root 1733 Mar 26 2021 ubuntu-keyring-2018-archive.gpg 6) As jan mentioned - what are you are trying to do seems to work fine for both of us.... hossman@slate:~/tmp/dockerbase$ ls -l total 4 -rw-rw-r-- 1 hossman hossman 117 Jun 1 21:08 Dockerfile hossman@slate:~/tmp/dockerbase$ cat Dockerfile FROM solr:9.2.1 USER root RUN apt-get update && \ apt-get upgrade --yes && \ apt-get install --yes locales hossman@slate:~/tmp/dockerbase$ docker build -t tmp-extened-solr . Sending build context to Docker daemon 2.048kB Step 1/3 : FROM solr:9.2.1 9.2.1: Pulling from library/solr 1bc677758ad7: Pull complete 0d0e0ecb256a: Pull complete 212512b6dedf: Pull complete 648d9d544695: Pull complete ae4d1091c493: Pull complete 5848e44a1a2f: Pull complete ddd2db2e437b: Pull complete e68c34067326: Pull complete 9ab7d551d9e8: Pull complete Digest: sha256:a46e8f2cc8b0e3e1a50be289cc0b4718e61fa5a5a745454c2da9e51a0312b612 Status: Downloaded newer image for solr:9.2.1 ---> 1834fb31cef8 Step 2/3 : USER root ---> Running in 3a0727367865 Removing intermediate container 3a0727367865 ---> 0592892b6da1 Step 3/3 : RUN apt-get update && apt-get upgrade --yes && apt-get install --yes locales ---> Running in a25792bbd3ae Get:1 http://archive.ubuntu.com/ubuntu jammy InRelease [270 kB] Get:2 http://security.ubuntu.com/ubuntu jammy-security InRelease [110 kB] ... -Hoss